30 week old Buffs stopped laying - Dog scare?

Hi fellow flocksters,
I am a little concerned and not sure how to proceed with my girls.

I have 5, 30 week old chickens that I raised from chicks- 3 Buff Orps and 2 EEs. They all started laying on time (some early) and we were really getting up to speed until ~2 weeks ago when things came to a screeching halt. I now have one EE laying and the others flat out quit. Not one brown egg in 10 days.

I have raised chickens for years and honestly believe I can exclude the basics (food water shelter) from the potential causes. Further, the girls get along with each other just fine and there is no pecking at all.

However, around 2 weeks ago the following happened:
1) We had a 2-day cold period in MD (just barely dipped below freezing)- it has been beautiful and in the 60's since.
2) I saw a large dog pouncing, clawing and slobbering all over the coop- I came out to find he had chewed up a lot of the wood. The girls were all hiding upstairs.

Now, I want to attribute their cease to the dog scare, but I am just not sure. I have had nightmare situations with a separate flock in the past and they never let up production (though they were production reds- so likely not apples : apples)

Since then I have artificially increased daylight by 2 hours, offered them some lovely classical music and maintained an extra clean and happy coop.

Has anyone else experienced this? Buffs are new to me - do they flat out quit at the first breath of winter?

If it is PTSD / shock related - will they ever return to laying? Will I wait 'till spring?

Since your food and water are good, they've been laying and only 30 weeks old, it is likely PTSD.
And since the nights are getting longer, it may take them longer to get over it than they would in spring or summer.
Cold really has nothing to do with ovulation unless it gets well below zero causing stress. Cold just happens to coincide with short days and long nights.

A few years ago, a Beagle got into a run and terrorized the birds. When I found him, the rooster had covered 2 hens in a corner and the dog was standing on the rooster barking. (I guess it was a good thing it was a beagle and not the neighbors huskies). The rest of the hens had all squeezed into nest boxes. The dog had pulled some tail feathers out.
That flock wouldn't come out of the coop for a week and except for the 2 eggs that were already in the assembly line and laid that day. I didn't get another egg out of that flock for 2 months.